Baked cereal bars are popular snacks which are sold in many varieties. The present invention deals with a product which is suitable for the manufacture of baked cereal bars consisting of a jacket of baked dough which surrounds a filling prepared with a nut paste which paste will be denoted also as nut butter in this patent specification. The nut paste preferably is peanut butter. Such kind of snack is described in WO 02/34054. When the filling consists of untreated peanut butter, snacks could not be properly prepared by a process of co-baking the dough jacket and the filling. At the prevailing baking temperature the peanut butter would deteriorate and fully liquefy, causing soaking the dough and even leakage from the jacket. Moreover the nut butter taste of the baked snack is seriously affected. A brittle, flaky and grainy filling with a poor flavour will result. The considerable difference in the water activities of common bread dough and untreated peanut butter causes undesired moisture migration and subsequent deterioration of the snack. A suitable but expensive solution consists in extruding a nut butter filling into an already baked hollow dough jacket. Several methods are known from the prior art for imparting bake stability to a snack filling prepared with peanut butter so that it can be co-baked with the dough jacket. U.S. Pat. No. 4,661,360 e.g. describes how a peanut butter filling containing 40–70 wt. % of fat can be imparted bake stability by surrounding it with a hydrophilic coating of corn syrup.
This method, however, like the other prior art methods requires processing which is too complex for industrial scale production and/or needs relatively expensive auxiliary ingredients. It is difficult to have the filling after baking retain the desired creamy texture characteristic of peanut butter. The complexity of the manufacturing process and/or the poor quality of the final product are the cause that baked snacks with a peanut butter filling, although having a high consumer appeal, are not commercially available presently.